The silver spire topping 1 World Trade Center is fully installed on the building's roof, bringing the structure to its full, symbolic height of 1,776 feet in New York. The new World Trade Center tower in New York knocked Chicago's Willis Tower off its pedestal as the nation's tallest building when an international panel of architects announced Tuesday the needle atop the skyscraper can be counted when measuring the structure's height. (ASSOCIATED PRESS / Mark Lennihan)

NEW YORK (AP) — They set out to build the tallest skyscraper in the world — a giant that would rise a symbolic 1,776 feet from the ashes of ground zero.

Those aspirations of global supremacy fell by the wayside long ago, but New York won a consolation prize Tuesday when an international architectural panel said it would recognize One World Trade Center as the tallest skyscraper in the United States.

The Council on Tall Buildings and Urban Habitat, considered a world authority on supersized skyscrapers, announced its decision at simultaneous news conferences in New York and Chicago, home to the 1,451-foot Willis Tower, which is being dethroned as the nation's tallest building.

Measuring the height of a building would seem to be a simple thing, but in the case of the new World Trade Center tower it is complicated by the 408-foot-tall needle atop the skyscraper's roof.

The council's verdict rested on a conclusion that the needle should be counted as part of the building's total height. Without it, the tower would be just 1,368 feet tall, the same height as the original World Trade Center. That would make it smaller than not only the Willis, but also a 1,397-foot apartment building being built a short subway ride away near Central Park.

Speaking at his office in New York, council chairman Timothy Johnson, an architect at the global design firm NBBJ, said the decision by the 25-member height committee had more "tense moments" than usual, given the skyscraper's importance as a patriotic symbol.

"I was here on 9/11. I saw the buildings come down," he said.

Over the past few months, the council had hinted that it might be open to changing its standards for measuring ultra-tall buildings, given a trend toward developers adding "vanity height" to towers with huge, decorative spires.

But the council also has a history of disallowing antennas in height calculations. The Empire State Building's landmark 204-foot needle isn't counted in its height measurement. Neither are the two TV antennas atop the Willis Tower, which had been the country's tallest building since it was completed — and named the Sears Tower — in 1974.

But in the end, there was unanimity on the committee that One World Trade Center's reach for 1,776 feet — a number that echoes the founding year of the United States — was an artistic architectural expression.

"This was a quest to put something meaningful and symbolic on that site because of the horrible history of what happened on that site," said Antony Wood, the council's executive director.

Tourists photographing the skyscraper Tuesday mostly agreed that when it comes to height measurements, this spire should count.

"For any other building, no. But for this one, yes," said Cary Bass, of Lake Mary, Fla., as he waited to enter the National Sept. 11 Memorial at the new skyscraper's feet. "Those people deserve it," he said, referring to the attack victims.

"It's a special building," said Paul Schlagel, visiting from Longmont, Colo.

When architect Daniel Libeskind won a public design competition for the World Trade Center master plan in 2003, his original vision was for a twisting, angular spire filled with hanging gardens.

Height was part of the appeal. At the time, his design of 1,776 feet would have made the so-called "Freedom Tower" the tallest skyscraper in the world.

Libeskind's drawings were always meant to be conceptual, though, and the real-world designs produced by architect David Childs and the tower's owner, the Port Authority of New York and New Jersey, reduced that glass spire to a more conventional cable-stayed mast, which would support broadcast equipment and a rotating beacon, visible for 50 miles.

That change, along with another that removed a layer of decorative cladding, had created some doubt about how the council might rule.

If they were to stand side by side, the Willis Tower would probably appear to be the larger building to most bystanders. In fact, someone standing in the Willis Tower's observation deck would have to look down to see One World Trade Center's roof.

This marks the second time that the Willis Tower has lost a "tallest" title in a disputed decision.

Back in 1996, the Council on Tall Buildings and Urban Habitat sparked controversy when it declared the Petronas Twin Towers in Malaysia taller than the Willis. That decision, like the one involving One World Trade Center, also rested on whether to count slender, decorative spires in the total height measurement.

Chicago Mayor Rahm Emanuel made light of Tuesday's decision.

"I would just say to all the experts gathered in one room: If it looks like an antenna, acts like an antenna, then guess what? It is an antenna," he told reporters.

Bella Engstrom, a tourist from Sweden visiting the World Trade Center site, said she thought any measurement of the building should stop at the highest point a person can stand in the tower.

"I think it's as high as you can go. You stop there," she said.

Kevin Corrigan, a union carpenter working at the Trade Center site Tuesday dismissed the height debate as an issue for academics, not workers on the job.

"Getting it built. That's what we care about," he said.

In a joint statement, the Port Authority, its marketing partner, the Durst Organization, and Childs' architectural firm, Skidmore, Owings & Merrill, said the building's creators had "long celebrated the height of 1,776 feet as an unwavering principal" of its design.

"This iconic building represents the resilience of America and today's decision recognizes One World Trade Center's rightful place in history," they said.

The new World Trade Center tower remains under construction and is expected to open next year.

When it does, it will be the world's third-largest skyscraper, behind the 2,717-foot Burj Khalifa in Dubai and the 1,972-foot Makkah Royal Clock Tower Hotel in Mecca, Saudi Arabia. Even that distinction may not last: Six even taller towers are under construction in Asia.